The present invention relates to heart ablation catheters.
Electrophysiological catheters apply radio frequency energy to produce burn lesions at selected points in the heart to correct arrhythmias. By destroying the cells that constitute defective conductive pathways, the arrhythmias are stopped. Typically, rigid electrodes, of ring form either partially or totally surrounding the catheter shaft, are used, though it is desirable at times to produce larger lesions than can be produced with such electrodes. By using a larger electrode, one could apply higher power, and by spreading the current at conventional current intensity over a larger area, the larger lesion can be produced. The diameter of such conventional electrodes, however, has been limited by the size of access hole that can be tolerated in the artery. Also, the length of these electrodes has been limited by the need to maintain maneuverability for the catheter to pass through tight curves in proceeding through the arterial system and into the heart.